Hoists



Aug. 21, 1962 w. E. BLAIN 3,050,152

HOISTS Filed NOV. 1, 1960 2 Sheets-Sheet i INVENTOI? Willard 5. Blair: If $824! ATTORNEY W. E. BLAIN Aug. 21, 1962 HOISTS 2 Sheets-Sheet 2 Filed Nov. 1, 1960 "Hl'hl -"Hl l lll l ll l hv n m E M ATTORNEY m w E. i M

3,050,152 HOISTS Willard E. Blain, Miami, Okla. (713 W. South Ave., Vinita, Okla.) Filed Nov. 1, 1960, Ser. No. 66,576 8 Claims. (Cl. 18241) This invention relates broadly to flexible hoists and more specifically to a device embodying an inflatable member formed from an impervious flexible material.

The device constituting the present invention is directed to the general class of column hoists. While hoists of this general type are known and used they have not achieved a great deal of success due primarily to height limitations that were necessarily imposed due to construction difliculties. If the question of height limitation was of no importance then it was possible to devise and construct hoists using pivoted members of the lazy tong type and also to employ a pair of telescopically arranged cylindrical members that used a fiuid medium to effect the raising of one member with respect to the other. In an effort to produce a hoist that could be elevated to a considerable height it was found to be necessary to have either a large cumbersome structure or one employing a plurality of brace members all of which resulted in a costly device and also one which easily acquired the appearance of permanent hoist.

The hoist of the present invention is of the mobile type and one which can be elevated to a considerable height, yet is readily capable of being collapsed and stored in a very small space.

One of the objects of the present invention is to provide portable type hoist having a flexible member mounted thereon and connected to a fluid medium supply for inflating and elevating said flexible member.

Another object is to provide a hoist of the mobile type having an elongated flexible member mounted thereon and engaged by friction drive rollers for elevating said member in conjunction with a source of air under pressure that is connected to said member.

Another object is to provide a hoist having an elongated flexible tubular member connected to a source or compressed air for elevating said tubular member and a platform carried thereby with a pair of rotatably driven squeeze rollers engaging said member to assist in elevating same and for sealing said member against the escape of the compressed air.

A further object is to provide a mobile hoist having a reel mounted thereon upon which an elongated flexible tubular member is wound with a closure cap secured to an end of said member and connected to a source of compressed air for inflating and elevating said member contemporaneous with the unreeling of said member.

Still other objects are to provide a mobile type hoist which is capable of being raised to rather high heights, which is positive in its operation and is economical of manufacture.

Other objects and advantages more or less ancillary to the foregoing and the manner in which all of the various objects are realized will appear in the following description which, considered in connection with the accompanying drawings, sets forth the preferred embodiment of the invention.

Referring to the drawings wherein the preferred embodiment of the invention is illustrated:

FIGURE 1 is a side elevational view of the mobile or portable hoist of the present invention;

FIGURE 2 is a horizontal sectional view of the hoist of the present invention, the view being taken on a plane indicated by the line 22 of FIGURE 1;

. FIGURE 3 is an end elevational view showing the $350,152 Patented Aug. 21, 1962 flexible member in its inflated and extended position with a platform carried by the upper end of said member;

FIGURE 4 is an enlarged detail sectional view showing the squeeze rollers engaging the flexible tubular member, the view being taken on a plane indicated by the line 4-4 of FIGURE 1;

FIGURE 5 is an end elevational view of the reel with the flexible tubular member coiled thereon; and

FIGURE 6 is an enlarged sectional view of the reel and flexible tubular member, the view being taken on a plane indicated by the line 6-6 of FIGURE 5.

Referring to the drawings there is shown in FIGURES 1 and 2 a mobile hoist unit embodying an elongated rectangular chassis frame including side members 10 and 11 joined together in spaced parallel relation by end members 12 and 14. The end frame members 12 and 14 having mounted thereon, in any suitable manner, axles 15 which in turn have wheels 16 rotatably mounted on the respective ends thereof. The end frame member 12 is provided with a pair of forwardly extending members 17 which are angularly disposed towards one another so as to terminate in a cap member 16 which may be secured by any suitable means to the free ends of said members whereby said members may serve as a tongue or coupling to facilitate the moving of the hoist from one location to another. The wheels 16 and axle 15 on the forward end of the frame unit are pivotally mounted on end frame 12 and the members 17 are connected to the axle 16 to facilitate the steering of the hoist unit.

The side frame members 10 and 11 each have secured thereto a pair of vertically extending braces or members 20 and 21 which are disposed in spaced relation to one another with the braces 20 on frame member 10 being in alignment with the braces 21 on frame member 11. The upper ends of the braces or members 20 and 21 have mounted thereon transverse supports 22 which in turn have secured thereto adjacent the ends thereof connecting members 23. Thus the members 20 and 21 together with the supports 22 and connecting members 23 define a guide member which has mounted on the upper surface of the members 22 and 23 a plurality of equally spaced roller guides 24. The roller guides 24 are freely mounted on shafts 25 which in turn have their ends secured in the vertically extending leg portions of brackets 26. The brackets 26 are so mounted upon the members 22 and 23 as to define a circular opening through which an elongated tubular flexible member 27 is adapted to extend. The rollers 24 are formed with concaved outer surfaces so as to provide a surface of substantially circular configuration for engaging and guiding the tubular member 27.

The tubular member 27 may be formed from any suitable flexible material that is impervious to any fluid medium so that upon the introduction of such a medium into the tubular member it will become inflated and remain in this condition until the fluid medium is permitted to escape. It has been found that a tubular member formed of Orlon fabric with a noeprene lining and having an internal diameter of five inches and an outer diameter of five and one-quarter inches is not only flexible but is also impervious to a fluid such as compressed air. It is to be understood that other materials may readily be employed in fabricating a flexible member which could be used in the present invention and that the specific illustnation is set forth simply as an example.

The tubular member 27 has one end 29 aflixed, in any suitable manner, to the outer surface of a reel or drum 30 which is rotatably mounted upon a shaft 31, FIGURE 6. The outer ends of the shaft 31 are mounted in brackets 32 that are carried by the frame members 10 and 11,

3 FIGURES 2 and S. The drum 30 has a flat clocklike spring 33 disposed at each end thereof which springs are connected to the drum and shaft 31. Thus when the flexible member 27 is uncoiled from the drum the springs 33 will be compressed about the shaft 31 so as to rewind the flexible member upon the drum.

As shown in FIGURES 1 and 4, the side frame members 10 and 11 have mounted in suitable bearing supports 35 the ends of a shaft 36 which has secured thereon a cylindrical roller 37, the length of which is substantially the distance between said frame members. The roller 37 has a second or cooperating roller 38 which is mounted upon a shaft 39 the ends of which are mounted in suitable bearing supports, not shown, in the ends 40 of a yoke member 41. The side frame members 10 and 11 have secured thereto, contiguous the rollers 37 and 38 a transverse brace member 43 which is drilled and tapped in the center portion thereof for the reception of the threaded end of a screw member 44. The threaded end of the screw member 44 extends through the brace 43 and is rotatably connected to the yoke 41 while the other end of the screw member 44 is provided with knob 45 to permit the ready rotation of the screw member 44 and the resultant movement of the yoke 41 and roller 38 towards or away from the roller 37. The roll ers 37 and 38 are positioned between the frame members 10 and 11 subjacent the guide member as defined by the members 20 and 21 and supports 22 and connecting member 23. The tubular flexible member 27 is entrained between the cylindrical rollers 37 and 38 before it passes between the roller guides 24 so that cylindrical roller 38 may be moved towards roller 37 and the two of them function as squeeze rollers for compressing the flexible member 27 therebetween and properly positioning and adjusting the member 27 with respect to said rollers.

The end of the tubular flexible member 27 that extends between the roller guides 24 has aflixed thereto in fluid tight relationship and by any suitable means, an enlarged collar or coupling member 46 which is provided with a smooth upper surface upon which a platform base 47 is secured. The platform base 47 is provided at its respective corners with vertically extending braces 48 which have horizontally extending guard rails 49 connected thereto. The platform base 47 is adapted to be of such size as to support one or more persons who are able to perform certain functions when the hoist has been elevated a prescribed distance.

The side and end frame members 10 and 14 respectively, have mounted thereon suitable power means such as a gasoline engine 51, of any conventional type, which is operatively connected by means of a gear drive unit 52 to an air compressor 53. The compressor 53 is in turn connected by a pipe 54 to anair receiver tank 55 that extends between and is mounted upon the side frame members 10 and 11. The air receiver tank 55 has connected to one end thereof a flexible conduit 56 which terminates in a suitable fitting -7 that is connected to the collar or coupling member 46 mounted on the end of the tubular flexible member 27. The fitting 57 is provided with an automatic safety relief valve 58 and with an air control valve 59 that is manually actuated by rod 60 which extends through the platform base 47 and terminates in a hand wheel 61. The collar member 46 also has connected thereto an air pressure gauge 62 that is mounted in the platform base 47 to indicate the pressure of the air in the flexible tubular member. The relief valve 58 is of an automatic pressure control type which is adapted to function when the tubular member 27 is being extended or retracted.

The side and end frame members 11 and 12, respectively, have mounted thereon a gasoline engine 63 that has a drive shaft 64 to which is secured a pulley 65. A belt is entrained about the pulley 65 and also about a second pulley 67 which is secured to a drive shaft 68 of a reversible gear reduction unit 69 that is mounted on 4. the side and end frame members 10 and 12, respectively. The gear reduction unit 69 has a drive shaft 71 projecting outwardly from the side thereof and a sprocket 72 is mounted thereon. A sprocket chain 73 is entrained about the sprocket 72 and also about a sprocket 74 mounted on an end of shaft 36 which carries the cylindrical roller 37. The cylindrical roller 37 isv rotatably driven and is designed to frictionally engage the tubular flexible member 27 to force said member between the roller 37 and its adjustable cooperating roller 38 prior to moving the flexible member between the guide rollers 24.

The side frame members It and 11 have mounted thereon adjacent the ends 12 and 14 outriggers 75 and 76, respectively. The outriggers are slidably carried in housings 77 and '78 that are secured to the bottom surface of the side frame members. The outer ends of the outriggers are provided with suitable jacks 79 to insure that the hoist is in a level position and suitably braced.

in the use and operation of the hoist as disclosed herein, the outriggers 75 and 76 are withdrawn from the housings 77 and 78 after the hoist has been positioned in the proper area. The engine 51 is then started to operate the compressor 50 so as to fill the air receiver tank. At this stage the collar member 46 and platform 47 are supported or resting upon the rollers 24 so that a person may climb upon the platform '47. When the operator is upon the platform 47 the control valve 59 may be opened by means of the hand wheel 61 which permits air to enter the flexible tubular member 27 for the purpose of inflating and elevating same through the roller guides 24. The engine 63 is started at about the same time as engine 51 and the gear reduction unit 69 is thus being driven While the air receiver tank is being filled.

The gear reduction unit 69 is provided with a suitable lever, not shown, for operatively connecting the drive shaft and sprocket 72 with said unit. The gear reduction unit is adapted to be operated by an attendant who also checks the operation of the air compressor. The sprocket 72 will rotatably drive cylindrical roller 37 through sprocket chain 73 and the roller 37 in conjunction with roller 38 will frictionally engage the flexible tubular member 27 and drive same. In the course of frictionally driving the flexible tubular member 27 the rollers 37 and 38 will cause said member to be withdrawn or uncoiled from the drum 30 and forced through the roller guides 24. At the same time that the rollers 37 and 38 are frictionally driving the flexible member 27 said member is being filled with air under a suitable head of pressure so that the rigidity of the tubular member 27 is being maintained by the pressure of the air and said flexible member is being elevated by the friction drive of the rollers. Thus the compressed air in conjunction with the rollers 37 and 38 cause the flexible member 27 and the platform base 47 to be elevated to the desired height. The roller 38 is through the yoke 41 and screw member 44 adjustably positioned with respect to the roller 37 so as to engage the flexible member to prevent the escape of the air therein and also to maintain the correct and proper engagement of the rollers 37 and 38 with the flexible member 27 so as to insure a friction drive of the member 27 by the rollers 37 and 38. As the flexible member 27 is being uncoiled from the drum 30 during its elevation the springs 33 are being coiled about the shaft 31.

In order to lower the platform 47 the gear reduction unit 69 is operatively connected to the sprocket 72 to drive same but in a reverse direction so that the roller 37 is driven in a reverse direction for the purpose of pulling the flexible member through the roller guides 24. As the flexible member is being drawn to the roller guides 24 by the frictional drive of the rollers 37 and 38 the spring 33 will cause the drum 30 to coil thereupon the flexible member 27. The control valve 59 is left open after the hoist is brought into operation and is only used to close off the air supply if a leak in the air line should develop. The withdrawing of the flexible member 27 through the guide rollers 24 by the frictional engagement of said member by the rollers 37 and 38 reduces the area of the flexible member between said rollers and the platform 47 thus causing a compression of the air within the flexible member 27 which increases the head pressure of the air resulting in the actuation of the relief valve 58. Thus the relief valve permits the escape or seepage of the air from the member 27 as it is being drawn through the guide rollers 24 by the rollers 37 and 38 and said relief valve will maintain the rigidity of the member 27 as it and the platform 47 are being lowered towards the frame members of the hoist. When the platform 47 has reached the lowest point of its travel the engines 51 and 63 can be stopped and the air receiver tank 55 vented to the atmosphere, after which the Outriggers can be stored in their respective housings and the hoist is then ready to be moved to another location.

Although the foregoing description is necessarily of a detailed character, in order that the invention may be completely set forth, it is to be understood that the specific terminology is not intended to be restrictive or confining and that various rearrangements of parts and modifications of detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

1 claim:

1. A portable hoist comprising a frame with wheels rotatably mounted thereon, a drum rotatably mounted on said frame, an elongated flexible member coiled upon said drum, one end of said flexible member being secured to said drum, a member secured to and closing the other end of said flexible member, said member connected to a source of fluid medium for inflating said flexible member and maintaining same in a rigid condition and means engaging said flexible member for uncoiling same from said drum for elevating said flexible member contemporaneous with the inflating of same with said fluid medium.

2. A portable hoist comprising a frame having wheels rotatably mounted thereon, a drum rotatably mounted on said frame, an elongated flexible member coiled upon said drum, a pair of cooperating rollers engaging said flexible member for uncoiling and elevating said flexible member from said drum, a member secured to and closing an end of said flexible member, said member connected to a source of fluid medium under pressure for delivering said fluid medium to said flexible member, said fluid medium inflating and maintaining said flexible member under pressure and in a rigid condition contemporaneous with the elevating of said flexible member by said rollers.

3. A portable hoist comprising a frame having wheels rotatably mounted thereon, a drum rotatably mounted on said frame, an elongated flexible member coiled upon said drum, a pair of cooperating rollers engaging said flexible member for uncoiling and elevating said flexible member from said drum, a member secured to and closing an end of said flexible member, said member connected to a source of fluid medium under pressure for delivering said fluid medium to said flexible member, said fluid medium inflating and maintaining said flexible member under pressure and in a rigid condition contemporaneous with the elevating of said flexible member by said rollers, said drum having coil springs associated therewith for winding said flexible member upon said drum upon the release of said fluid medium from said flexible member.

4. A portable hoist comprising a frame having wheels rotatably mounted thereon, a drum rotatably mounted on said frame, an elongated flexible member coiled upon said drum, a pair of cooperating rollers engaging said flexible member for uncoiling and elevating said flexible member from said drum, a member secured to and closing an end of said flexible member, said member connected to a source of fluid medium under pressure for delivering said fluid medium to said flexible member, said fluid medium inflating and maintaining said flexible member under pres sure and in a rigid condition contemporaneous with the elevating of said flexible member by said rollers, one of said cooperating rollers being adjustable with respect to the other roller to vary the pressure applied to said flexible member by said rollers.

5. A hoist of the type as set forth in claim 2 including a plurality of guide rollers carried by said frame and engageable with said flexible member intermediate said cooperating rollers and said member.

6. A portable hoist comprising a frame having Wheels rotatably mounted thereon, a drum rotatably mounted on said frame, an elongated flexible member coiled upon said drum with one end of said flexible member being secured to the drum, a pair of cooperating rollers carried by said frame and frictionally engaging said flexible member for uncoiling and elevating said flexible member from said drum, power means mounted on said frame and operatively connected to one of said rollers for rotatably driving same, the other of said cooperating rollers being adjustable with respect to the first named cooperating roller to vary the pressure applied to said flexible member by said rollers, a platform member secured to and closing the other end of said flexible member, a source of compressed air carried by said frame, said platform member being in fluid communication with said compressed air for delivering same to said flexible member, a relief valve carried by said platform member to permit the release of the compressed air from said flexible member, said flexible member being inflated and maintained in a rigid condition by said compressed air contemporaneous with the frictional engagement of said flexible members by said cooperating rollers for elevating said platform member.

7. A portable hoist comprising a frame having wheels rotatably mounted thereon, a drum rotatably mounted on said frame, an elongated flexible member coiled upon said drum with one end of said flexible member being secured to the drum, a pair of cooperating rollers carried by said frame and frictionally engaging said flexible member for uncoiling and elevating said flexible member from said drum, spring means connected to said drum for rewinding said flexible member upon the drum, power means mounted on said frame and operatively connected to one of said rollers for rotatably driving same, the other of said cooperating rollers being mounted in a yoke member, means carried by said frame and engageable with said yoke for adjustably positioning said other roller with respect to the driven roller to vary the pressure applied to said flexible member for frictionally engaging and elevating said flexible members, a platform member secured to andclosing the other end of said flexible member, a source of compressed air carried by said frame, a conduit connecting said platform member and flexible member in fluid communication with said compressed air, said flexible member being inflated and maintained in a rigid condition by said compressed air contemporaneous with the frictional engagement of said flexible member by said cooperating rollers for elevating said platform member, said cooperating rollers in frictionally engaging said flexible member insures the retention of the compressed air Within said flexible member between said platform member and the point of engagement of the flexible member by said cooperating rollers, and a relief valve in said conduit to permit the release of the compressed air from said flexible member and the winding of the flexible member upon said drum.

8. A portable hoist comprising a frame having wheels rotatably mounted thereon, a. drum rotatably mounted on said frame, an elongated flexible member coiled upon said drum with one end of said flexible member being secured to the drum, a pair of cooperating rollers carried by said frame and frictionally engaging said flexible member for uncoiling and elevating said flexible member from said drum, spring means connected to said drum for rewinding said flexibl member upon the drum, power means mounted on said frame and operatively connected to one of said rollers for rotatably driving same, the

7 other of said cooperating rollers being mounted in a yoke member, means carried by said frame and engageable with said yoke for adjustably positioning said other roller with respect to the driven roller to vary the pressure applied to said flexible member for frictionally engaging and elevating said flexible members, a platform member secured to and closing the other end of said flexible memher, a guide member supported upon said frame superjacent said cooperating rollers, a plurality of roller guides mounted upon said guide member and engageable with said flexible member intermediate said platform member and said drum, a source of compressed air carried by said frame, a conduit connecting said platform member and flexible member in fluid communication with said compressed air, said flexible member being inflated and maintained in a rigid condition by said compressed air contemporaneous with the frictional engagement of said flexible member by said cooperating rollers for elevating said platform member, said cooperating rollers in frictionally engaging said flexible member insures the retention of the compressed air Within said flexible member between said platform member and the point of engagement of the flexible member by said cooperating rollers, and a relief valve in said conduit to permit the release of the compressed air from said flexible member and the Winding of the flexible member upon said drum.

References Cited in the file of this patent UNITED STATES PATENTS 519,499 Ellis May 8, 1894 2,130,993 Dubilier Sept. 20, 1938 2,609,177 Hughes Sept. 2, 1952. 2,738,039 Hamilton Mar. 13, 1956 2,799,368 Alter July 16, 1957 

